Grate bab



Feb. 5, 1929. 1,701,150

H. A. ELLIS Original Filed Nov. 14, 1925 Patented Feb. 5, 1929.

UNITED stares earner easier.

HUMPHREY A. ELLIS, OF PHILADELPHIA, PENNSYLVANIA.

GRATE BAR.

Application filed November 14, 1925, Serial No. 68,975. Renewed June 30, 1928.

The object of this invention is to provide improvements in grate bars, for chain, stationary, and dumping grates, and part cularly relative to the normally upper port on thereof, or in other words to that portion which is closely adjacent to the fire bed or the fuel superimposed thereupon.

Another object is to provide a construction of grate bar which, when a plurality of such bars are operatively assembled together, presents a multitude of apertures comprising a maximum percentage of the effective supporting surface of the grate, each of said apertures, instead of extending directly through a bar, being spanned but not closed by a subimposed baflie, which serves to pre vent low grades of coal, or similar tine fuel, from percolating tl'ierethrough, even to the smallest coal dust, or culm. Such a large aggregate area of openings thus insures maximum combustion by reason of the even d1stribution of the oxygen supplied to the firebed under a forced draft.

A further object is to provide in a set of such bars, when operatively assembled to form a grate, a series of pairs of converging, diagonally or obliquely exten'dmg channels, those of each pair meeting a short distance beneath the plane of the upper surface of said grate, and the air currents within each pair of said channels uniting, but, instead of neutralizing each other and thus resulting in a direct upward flow after passing from the common discharge outlet, creating diverging currents of air throughout the body of fuel upon the grate, and with the result that the very line particles of low grade fuel are ignited more readily by the divergent nature of the blast, and the fuel is thus subjected to maximum combustion without being lifted freely or blown from the firebed towards the stack before being consumed.

Still another object is to so construct a grate bar forming a unit in a composite grate of this character, that when being cast (as is customary in such articles) eliminates all necessity for coring, with the result that the expense of manufacture is the same as for common, straight-channel bars, and is decreased far below what would be the cost of production, to obtain the same results by other designs.

Still further details of the construction and operation of the inventionvare fully brought out in the following description,

when read in conjunction with the accompanying drawings in which Fig. 1 is a side elevation of a complete bar and the cooperating portions of two adjacent bars, each of which embodies one form of the invention;

Fig. 2 is a top plan view of two aligned series of bars such as are shown in Fig. 1; Fig. 3 is a vertical section on the line 3-3 of Fig. 1; Fig. 4 is a vertical section on the line H of Fig. 1; Fig. 5 is an elevation of one end of a bar; Fig. 6 is the elevation of the opposite end of a bar; and Fig. 7 is diagrammatic view showing the relation between, the union of, and the effect produced by, the air currents when directed or controlled by channels in the bars arranged in accordance with the invention.

Referring to the drawings, a bar embodying the present invention comprises a body portion 10, having its normal under portion so shaped at 11 as to permit its being supported by any desired well-known type of frame (not shown), and in one longitudinal direction terminating in an extension 12, which normally extends beneath the bar next adjacent thereto and serves to catch and retain the ashesv from the grate surface thereabove, when in chain grates said bars separate as the frame supporting said lastnamed bar starts over the usual idler (not shown), and until said first-named bar also reaches and commences to pass about said idler.

Transversely, each bar comprises a longitudinally extending rib 13, having a preferably undulating upper surface 14-, which directly supports the fuel of the firehed. while extending laterally from the opposite sides of said rib is a series of spaced lugs 15, the upper surfaces of which form substantially flush lateral continuations of the corresponding surface of said rib, recesses 16 being thus provided between adjacent lugs, andthe corresponding recesses of adjacent bars cooperating to form preferably oblong discharge apertures 17.

Beneath said series cally staggered with respect thereto is a second series of lugs 18, each of said lastnamed lugs spanning and being in alignment with and partially obstructing the aperture 17 thereabove to prevent particles of fuel from falling therethrough and into the ashpit or other chamber beneath. Bet-ween adjacent lugs 18 in said second series, air receiving apertures 19 are formed, while of lugs 15 and vertibetween adjacent lugs 15 and 18 in said first and second series are disposed diagonally extending channels 20, connecting each receiving aperture in opposite directions with two neighboring discharge outlets, or in other words, a pair of converging channels 20 being operative to lead and unite currents of air from two adjacent receiving apertures, after which said currents are discharged through the fuel-supporting surface of the grate, and are then disseminated in divers paths through the fuel thereon. The angular direction of the channels 20 is such that their lower walls (that is, the upper surfaces of the lugs 18) have a slant that is determined by the angle of repose and internal coefficient of friction of the fuel in use, or such an angle that prevents said fuel from running over each lug and falling therefrom into the ashpit or other chambers.

Aside from the novel construction of each bar of a composite grate, as hereinbefore described, one of the principal novel features of the invention is illustrated by Fig. 7. Here are indicated five neighboring lugs of the two series 15 and 18 and the channels formed between them. The light lines extending through said channels indicate the directions taken by air currents under the influence of a forced draft from below the grate. Two of these currents are seen to converge from the opposite sides of a central lug 18 of the lower series, and in uniting and passing together through the aperture 17, formed between the two adjacent lugs 15 of the upper series immediately thereabove, create diversely related currents in the fire bed roughly as shown. In actual practise the current, instead of being perfectly shaped as idicated, in reality diffuses through the fuel mass, and the air in each pair of adjacent currents above the grate surface eventually diffuses to such an extent as to insure a positive flow of fresh air through all portions of the fuel. The diverging spiral lines do, however, represent the general direction of the said air currents.

Having thus described my invention, what I claim and desire to protect by Letters Patent of the United States is 1. A grate bar, comprising a longitudinally extending body portion, a series of lugs extending laterally therefrom upon one side and spaced apart to provide recesses therebetween, and a second series of lugs also extending laterally therefrom and beneath said first series, the lugs of said second series also being spaced from one another to provide recesses therebetween, and from the lugs of said first series to provide converging channels connecting the recesses of the respective series.

2. A grate bar, comprising a longitudinally extending body portion, a series of lugs extending laterally therefrom upon one side and spacedapart to provide discharge recesses therebetween, and a second set of lugs also extending laterally therefrom and beneath said first series, the lugs of said second series also being spaced from one another to provide receiving recesses therebetween, and from the lugs of said first series to provide converging channels connecting said receiving recesses to said discharge recesses.

3. A grate bar, comprising a longitudinally extending body portion, a series of lugs extending laterally therefrom upon one side and spaced apart to provide discharge recesses thcrebetween, and a second set of lugs also extending laterally therefrom and beneath said first series, the lugs of said second series also being spaced from one another to provide receiving recesses therebetween, and from the lugs of said first se'ies to provide converging channels connecting each discharge recess to two spaced receiving recesses, and the union of said channels being below the fuel-supporting surface of the bar.

4. A grate bar, comprising a longitudinally extending body portion, a series of lugs extending laterally therefrom upon each side thereof and the lugs upon each side being spaced apart to provide recesses therebetween, and a second series of lugs upon each side of said body portion, and extending laterally therefrom beneath said first series, the lugs of each of said second series also being spaced from one another to provide recesses therebetween, and the lugs of second series being spaced from the lugs of the corresponding first series to provide converging channels separating the first and second series of lugs upon each of the opposite sides of said body portion.

5. A grate formed of parallel cooperating bars, each comprising a longitudinally extending body portion, a series of lugs extending laterally therefrom upon each side thereof and the lugs upon each side being spaced apart to provide recesses therebetween, and a second series of lugs upon each side of said body portion, and extending laterally therefrombeneath said first series,

the lugs of each of said second series also being spaced from one another to provide recesses therebetween, and from the lugs of the corresponding first series to provide converging grooves between the respective series of lugs upon the respectively opposite sides of said body portion, and the cooperation of adjacent bars serving to inclose the grooves between said lugs to form channels, and to inclose said recesses to create receiving and discharge apertures.

6. A grate formed of parallel cooperating bars, each comprising a longitudinally extending body portion, a series of lugs extending laterally therefrom upon each side thereof and the lugs upon each side being spaced apart to provide recesses therebe tween, and a second series of lugs upon each side of said body portion, and extending laterally therefrom beneath said first series, the lugs of each of said second series also being spaced from one another to provide recesses therebetween, and from the lugs of the corresponding first series to provide converging grooves between the respective series of lugs upon the respectively opposite sides of said body portion, and the coop eration of adjacent bars serving to inclose the grooves between said lugs to form channels, and to inclose said recesses to create receiving and discharge apertures, said discharge apertures being in the plane of the fuelsupporting surface of the grate.

7 A grate formed of parallel cooperating bars, each comprising a longitudinally extending body portion, a series of lugs extending laterally therefrom upon each side thereof andthe lugs upon each side being spaced apart to provide recesses therebetween, and a second series of lugs upon each side of said body portion, and extending laterally therefrom beneath said first series, the lugs of each of said second series also being spaced from one another to provide recesses therebetween, and from the lugs of the corresponding first series to provide converging grooves between the respective series of lugs upon the respectively opposite sides of said body portion, and the cooperation of adjacent bars serving to inclose the grooves between said lugs to form channels, and to inclose said recesses to create receiving and discharge apertures, said receiving apertures being between the body portions of adjacent bars, and said discharge apertures being in the plane of the fuel-supporting surface of the grate.

In testimony whereof I have afiixed my signature.

HUMPHREY A. ELLIS. 

